I have a 95lt1 with a 4L06e in 54 international pickup. The engine came out of a 95 buick roadmaster, it runs great and gets about 20-24mpg on the highway. The problem i have run into is when i pull my little camper the mileage drops to like 5mpg and I dont think i am doing the tranny any favors. I am thinking a shift kit, and a trans cooler and i think an rv cam would help out any suggestions on a cam????

 

I'd look into a cc503 it's a allaround power making cam had one in my 97 and loved it.

 

Contact this guy, he'll get you setup with a cam that'll fit your needs:
http://elliottsportworks.com/

 

I am wondering if a cam swap will help with the camper though. If climbing a hill at WOT in 2nd gear, I say sure. But too much cam will only hurt highway cruising mpg. It's not like you have a high winding rpm cam in right now, an RV cam will have similar specs.
Your engine is allready geared towards low-mid rpm torque with decent fuel economy.

The LT1 you installed will have the higher flowing iron LT1 heads on it, and has the same cam the Vortec 305/350 truck engines have. It's specs are 192º/197º 0.412"/.428" on a 111ºlsa.

IMO It really depends if you mostly do low throttle 4th/OD or high throttle/WOT towing in 2nd gear.

The Caprice 5.7 LT1/4.3 L99 V8 also uses the smaller 70mm(2-3/4") MAF-same as the 4.3 Vortec V6. The 305/350/454 Vortec and 1994-2002 LT1/4 and LS1 uses the 75mm(3.0") MAF. The 1999+ 4.8/5.3/6.0/8.1 Vortec truck and 2001-2004 LS6 in the ZO6 Vette use the 85mm(3-1/4")MAF.

What gears are you running? In my 1997 reg cab shortbox-about 4000lbs with 3.08 gears and 27" tires(stock) my truck would unlock the TCC and occasionally downshift to 3rd gear to climb this one particular hill when cruising at 70mph.
I installed 4.10 gears and the same hill, at the same speed would use slightly more throttle than flat cruising, but the trans would stay in 4th gear(0.70:1) and the TCC stayed lock and easily climb the hill.
Swapping to a lower rear gear will accomplish more for your towing capability and trans durabilityl.

Your engine is rated at 260hp@5000rpm 330 lb/ft@3200rpm at WOT. Lets see how much is actually seen at the rear tires based on gearing.

Overdrive
(I'm going to exclude torque converter multiplication from this)
engine torque x trans gearing x rear gear ratio
330lb/ft x 0.70:1 x 3.08
=711 lb/ft torque at the rear tires

Now simply going from 3.08's to 4.10's
330 lb/ft x 0.70 x 4.10
=947 lb/ft torque at the rear wheels

Lets run the same numbers, but lets tow in 3rd gear
330 x 1 x 3.08 (obviously same at 330 x 3.08)
1,016 lb/ft at the rear wheels

330 x 1 x 4.10 (same as 330 x 4.10)
1,353 lb/ft at the rear wheels

Going to a lower rear gear, will help reduce strain on your u-joints, driveshaft, transmission and engine. The engine will turn some morerpm though.

With an OD trans 700r4/4l60e
3.08 gears with a 0.70:1, with a 28" tire revs 1800rpm@70mph.
4.10 gears with a 0.70:1, with a 28" tire revs 2400rpm@70mph.

With a 1:1 trans ratio
3.08 gears with 1:1 trans gear and 28" tires revs 2587rpm@70mph.
4.10 gears with 1:1 trans gear and 28" tires revs 3400rpm@70mph.

I went from 3.08's to 4.10's and my city fuel economy went up, and I dropped about 2mpg at civil highway speed. 4.10's and 27" tires were a bit much for 80+mph speeds for any amount of time.

A good PCM tune would help your LT1/4l60e combo as well, as would a shift kit, a trans cooler is a good idea as well as sustained TCC lock towing raises fluid temps considerably.

peace
Hog

 

Holy loads of info! Agreed a tune and gear swap (if needed) would help more than a cam alone. An external trans cooler is always a good idea. Here's a few tuners that can do whatever you want with an LT1 pcm. Ed at fastchip has been doing fantastic work for years, I've also had good work from Bryan at PCM4less. There are many other tuners out there but I've only had work done by these two so that's all I can comment on.

http://www.fastchip.com/

http://www.pcmforless.com/

 

I think I may have an aftermarket cam from the lt1 we had in the blazer. Had 3 dyno pulls on it. Had collapsed lifter so we removed it. Also have some GOLEN engines cnc heads also. I can check for cam tomorrow. Was installed on 97 5.7 lt1

 

I was thinking gears to, just forgot to mention that. most likely my best option as i am running a 2:73 i will most likely go with a 3:73 whats your thoughts on that?

 

I went from 3.08 to 4.10's and it was great, unless I wanted to do some 80+mph cruising.

Your towing situation will be just great, and I bet you dont drop much for fuel economy unloaded, and your loaded economy will be greatly improved.

3.73's is a great gear, for 26-29" tire height,all around driver. If you are above 31" I suggest a 3.90:1.

I agree with 96LT1355Z28 recommendations, those guys do great work with LT1's although I heard that Ed is doing mail order only due to illness.

peace
Hog